The present invention relates to a ship with mooring means, comprising a tube or turret which is mounted on the ship for rotation about a vertical axis relative to the ship by means of a bearing structure which can absorb axial and radial forces, such as a combined axial/radial bearing, of which bearing structure at least the part absorbing the axial forces is mounted on the tube with the outer ring of the bearing supported on the ship and the tube having at its lower end means for fastening anchor chains or cables.
Such a ship is disclosed in U.S. Pat. No. 4,660,494. In such a known ship, the rotary tube is supported in a top and bottom carrier projecting beyond the bow of the ship, the top end of the rotary tube being fastened to the inner ring of an axial/radial bearing whose outer ring is fastened to the bearing structure of the ship which projects beyond the bow of the ship. The rotary tube is supported by a radial bearing near its lower end.
These bearings are made with great precision and make it possible for the ship to turn with minimum resistance about the tube which is secured to the bottom of the body of water with anchor chains. This is a disadvantageous location for the bearing, however, because the bow of the ship can be subjected to powerful movements and wave forces.
U.S. Pat. No. 3,440,671 provides within the hull of the ship a cylindrical hollow chamber, in which is disposed a tubular element which has buoyancy and has means for the securement of anchor chains and is provided with sets of wheels fitted at intervals along its periphery, permitting turning of the ship and tubular element relative to each other. This mutual support of the ship and tube also permits the relative turning even if as a result of the movements of the ship deformations of the walls of the cylindrical tube occur. This cylindrical tube becomes deformed to an oval shape under certain load conditions. If the sets of wheels are self-adjusting, then sufficient play is available to tolerate such deformation.
But if it is desired to use a precisely made axial/radial bearing working with considerably less friction than the wheels of U.S. Pat. No. 3,440,671, or the combination of an axial bearing with a radial bearing at points which are spaced apart as in U.S. Pat. No. 4,660,494, then this is not possible with the known constructions, because the axial/radial bearing is exposed to the deformation imposed by the racking of the hull under the force of the waves.
Another such construction in which a reinforcing ring for the bearing is nevertheless subjected to the racking of the hull under the force of the waves, because it is directly connected to the hull, is found in U.K. patent Appln. 2 150 517A; and this construction also is inconsistent with the provision of a precisely made bearing.